Firstly, note that Schema.org and Google’s Rich Snippet Testing Tool are not universally linked. That is, just because something is valid according to Schema.org, it may not meet Google’s own requirements.

For an Article type, here is Google’s exact code, which will validate the Rich Snippet Testing Tool:

Schema.org does not require images and website logo for every article, but Google does.
Due to the fact that Google uses this markup for different display options (carousel etc), its requirements differ from the requirements of Schema.org
For example, the publisher type for an Article can only be an Organization, while Schema.org allows the use of a Person type.

Where do you implement the code? It looks to me as if it should go in the header file, but there’s a lot of extra code there and (if I’m right about it being in the header then I think) it duplicates code already in my header.

Even after following your steps, I’m getting the same error in Structured Data testing tool. The same error “The property logo is not recognized by Google for an object of type WebPage”. Can you please have a look at it and tell me what’s wrong. Website: https://predictx.in